While I agree that there are some strong similarities between preparing cocktails and cooking, I don't feel that having them on this site is going to benefit us. I know that on the cooking websites that I follow, all alcohol and brewing related articles get entirely ignored by me as I am not their target audience. When I need to pair food with alcohol I can, but it's just not an overriding passion of mine. That said, the real reasons that I think would be detrimental are as follows:
Shared front page - I don't think that professional bartenders are going to want to wade through a front page full of cooking to get to the questions that interest them, and I know I don't want to do on the opposite case.
Recipes are intergral to bartending - We have tried really hard to make sure that this site didn't become a recipe swap, and you can't talk bartending or cocktails without them. Just like baking, you work off a recipe in bartending and I don't see how you would avoid that.
Increased noise - One of the things that makes the stack exchange system work so well is that it cuts down on the noise that forums and the like generate. Putting two subjects together in the same site is going to increase the noise level over all and make those little comment dustups happen a lot more frequently.
I'm sure that there are more and Im just as sure there are a few good reasons to do it, but this is what popped into my head.